Process for the preparation of amorphous copolymers of ethylene

ABSTRACT

A process for the preparation of amorphous copolymers of ethylene, one or more other Alpha -alkenes, and optionally one or more compounds containing more than one C=C bond, using a catalyst comprising an aluminum dihalide, a vanadium compound and an organo metal compound, the catalyst being dispersed in a liquid dispersing agent.

' United States Patent Field of Search ..260/88.2, 80.7.8, 80.7

Van Den Berg 1 Dec. 5, 1972 PROCESS FOR THE PREPARATION OF [56] References Cited AMORPHOUS COPOLYMERS OF ETHYLENE UNITED STATES PATENTS Inventor: Cornelis E. P. v v Den g Natta et Geleen Netherlands 7 3,376,248 4/1968 Kirkland ..260/33.6 3,518,237 6/1970 Duck et a]. ..260/80.78 [73 I Assignee: Stamicarbon N.V., Heerlen, Netherkinds Primary Examiner-James A. Seldleck v 1 Assistant Examiner-Richard A. Gaither I96) A!l0rney- CuBhmun, Darby 84 Cuahman [2! l Appl. No.: 837,885

[57] ABSTRACT [30] Foreign Application Priori D t A process for the preparation of amorphous copolymers of ethylene, one or more other a-alkenes, July 1, 1968 Netherlands ..6809302 and optionally one or more compounds containing more than one C C bond, using a catalyst compris- [52] US. Cl ..260/80.7, 260/8078, 260/882 R ing an aluminum dihalide, a vanadium compound and [51] Int. Cl. ..C08f 15/40, C08f 17/00, C08f 1/56 an organo metal compound the catalyst being dispersed in a liquid dispersing agent.

9 Claims, No Drawings PROCESS FOR THE PREPARATION OF AMORPHOUS COPOLYMERS OF ETHYLENE The invention relates to a process for the preparation of amorphous copolymers of ethylene with at least one other a-alkene or copolymers of ethylene, another aalkene and one or more compounds with more than one C=C bond. The invention particularly relates to a process for the preparation of sulphurcurable amorphous copolymers of ethylene, one or more other a-alkenes, and one or more compounds containing at least two non-conjugated C=C bonds. It is well known that these copolymers can be prepared in a liquid dispersion agent using as catalysts for the reaction a vanadium compound and an Organo-aluminum dihalide. By curing with sulphur, the copolymers obtained with this catalyst can be transformed into products possessing good mechanical properties.

The object of the invention is to provide an improvement to the process for producing such copolymers.

lt has been found that the catalytic activity can be greatly increased by using a catalyst comprising a vanadium compound, an organoaluminum halide, and an organic alkali metal compound in an amount not larger than 60 mole percent calculated on the amount of aluminum compound.

The invention consequently relates to a process for the preparation of amorphous copolymers by polymerization of ethylene, at least one other d-alkene and, if so desired, one or several compounds with more than one C=C bond, using a catalyst containing a vanadium compound and Organo-aluminum dihalide, in a liquid dispersing agent, and an organic alkali metal compound in an amount not larger than 60 mole percent calculated on the amount of the aluminum compound.

a-alkenes that can be used as the monomer in addition to ethylene, are the a-alkenes containing from one to 12 carbon atoms, such as propylene, butene-l, pentene-l, hexene-l octene-l, their branched isomers, such as 4methylpentenel styrene, a-methylstyrene, or mixtures of these compounds Particularly suited is propylene or propylene or propylene with butene-l.

The polyunsaturated compound may be any containing at least two C=C bonds and may be either aliphatic or alicyclic. The aliphatic polyunsatured compounds normally contain three to 20 carbon atoms, with the double bonds being either conjugated or non-conjugated. Examples of such compounds are: l-3-butadiene, isoprene, 2,3-dimethyl butadiene l-3, 2-ethyl butadiene 1 3, piperylene, mycene, allene l,2-butadiene, 1,4,9-decatrienes, l-4-hexadiene, 1,5-hexadiene and 4-methyl hcxadiene l-4. The alicyclic polyunsaturated compounds, whether or not containing a bridge group, may be either monocyclic or polycyclic, and may contain one or several halogen atoms. Normally use can be made e.g. of the alkyl norbornadienes; the alkylidene norbornenes, in particular the 5-alkylidene norbornenes-2 in which the alkylidene group contains one to 20 and preferably one to eight carbon atoms, the alkenyl norbornenes, in particular the 5-alkenyl norbornenes-2 in which the alkenyl group contains three to 20 and preferably three to carbon atoms, e.g. 5-(2'methyl-2'-butenyl) norbornene-Z and 5-(3'methyl-2-butenyl)-norbornene-2; 2 dicyclopentadiene and the polyunsaturated compounds of dicyclo (2,2,l)-heptane, dicyclo-(2,2,2)-octane, dicyclo- (3,2,l)-octane and dicyclo-(3,2,2)-nonane in which at least one of the rings is unsaturated. Further, compounds such as 4,7,8,9-tetra-hydroindene and isopropylidene tetrahydroindene may also beused. In particular, use is made of dicyclopentadiene, 5- methyleneor 5-ethylidiene norbornene-2 or hexadiene 1-4. Mixtures of the abovementioned compounds may also be used.

Normally, only slight amounts (e.g. 0.5 10 percent by weight) based on the total polymers of these polyunsaturated compounds need be incorporated in the amorphous polymer, to achieve adequate curing. Large amounts may also be used, however.

The organic group in the organo-aluminiumhalid used as the catalyst component may be an aryl, aralkyl or alkaryl group, but preference is given to an alkyl group, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, hexyl or octyl. Very good results are obtained with monoethyl-aluminum dichloride. If desired, the Organo-aluminum halide may contain a slight amount, e.g. up to 10 percent by weight, of a diorgano-aluminum halide. For the vanadium compound component in the catalyst, preference is given to a vanadium compound that is soluble in the dispersion agent used for the polymerization. In particular, VOCl or VOCl,, whether or not in combination with TiCl, may be used.

If desired, other substances may be added to the catalyst, such as slight amounts of a compound with free electron pairs, e.g. water, and alcohol, oxygen or Lewis bases.

The ratio between the aluminum compound and the vanadium compound may be varied within wide limits, e.g. between 1 l and l, but is preferably between 3 l and 15 1. In the continuous realization of the process, the catalyst components, whether or not dissolved in a dispersing agent, are preferably directly supplied to the polymerization zone. The organic alkalimetal compound to be used as a component of the catalyst according to the invention, may be represented by the formula MR, where M denotes an alkali metal and R an alkyl group with one- 12 carbon atoms, a cyclo-alkyl group or an aryl group. Organic lithium compounds are especially useful and in particular, very good results are obtained with normal butyl lithium. Organo compounds of the other alkali metals, however, are also suitable. Even small amounts of the organic alkali metal compound, e.g. approximately 2 mole percent calculated on the amount of the aluminum compound, increase the activity of the catalyst. If more of the alkali metal compound is added, the activity usually increases to maximum after which with the addition of more of the alkali metal compound, a decrease sets in. The highest activity is achieved if the organic alkali metal compound is used in an amount of 10 40 mole percent calculated to the amount of aluminum compound.

The copolymerization reaction is normally carried out at a temperature between 50and +l20 C, preferably between l0and 50C. The pressure will generally be between 1 and 50 atmospheres, but higher or lower pressures may also be used. Preferably, the process is carried out continuously. The dispersing agent may be any liquid that is inert to the catalyst, e. g., a more or less saturated aliphatic hydrocarbon such as butane, pentane, hexane, heptane or mineral oil fractions, aromatic hydrocarbons, such as benzene or toluene or halogenated aliphatic or aromatic hydrocarbons, such as tetrachloroethylene.

yield a product of excellent properties, which is suited for use in car tires. The copolymers may further be used in the production of bicycle tires, conveyor belts, footwear, flooring material and sealing strips.

It is convenient to execute the process under such 5 The copolymers made by the process according to temperature and pressure conditions that one or the invention can be vary readily vulcanized by heating several of the monomers used, particularly the a-althem together with sulphur at l250 C, preferably kene, e.g. propylene, will be present in so large a ua at l40l70 C. Free radical sources, such as peroxtity that it will act as the dispersing agent. The process to s may be added but this is hot necessai'yaccording to the invention can be carried out in a if so desired the copbiymers Obtained according to polymerization reactor filled with gas and liquid, but the invention y be Processed to Crumb, sheets preferably in a reactor completely filled with liquid. sksihs, bales The molecular weight f the eopolymers may The following examples serve to elucidate the invenmally be influenced by means of a so-called chain-coni tibh, without restricting its scope in y y Whattrolhhg agent acetylene Hydrogen may he usedv soever. The intrinsic viscosity is measured in decalin at advantageously in the process according to the inveni C and at a concentration of i g of cbpbiymer P tion, particularly if it is used in a polymerization reactor litre completely filled with liquid. Very small amounts of hydrogen have a sufficient effect on the molecular EXAMPLE I weight, but will be soluble in the polymerization medi- Continuous and separate flows of 0.9 l/h of heptane um, so that under the prevailing polymerization prescontaining the dissolved metal organic compounds, 0.9 sure and temperature conditions no gaseous hydrogen l/h of heptane containing 0.45 mole of dissolved will be present in the polymerization reactor. VOCl and 0.2 l/h of heptane containing moles of dis- After the reaction is substantially complete, the solved ethylidene norbornene were fed under moisturecopolymer is recovered from the reaction mixture oba yg o d ti n t a ta a t r 0 3 L tained in the copolymerization. The recovery may be Capacity, with a Water-cooled Wail, ahd agitator, and made with or without addition of water, steam or feed and discharge apertures F a Continuous methanol; prior to this operation the catalyst may be flow of a gas mixture Consisting of 64 libi'bbht y deactivated, e.g. with water and alcohol or an acid. "Oihme 0f P py 27 Percehii y Volume of The copolymer thus prepared may be admixed with ethyiehe, and 9 Percent y Voiume of y g Was fed the customary chemicals, Such as zinc oxide, Stearic to the reactor. The feed rate was to chosen that not less acid, sulphur, anti-oxidants, vulcanization accelerators, than 50 percent offhe gas Issued from the reactor m e. g. tetramethyl thiuramdisulphide, tackifiers, dyes and unconverted form a reflux condensor' The reactor pressure was 1 at gauge, and the pigments. If so desired, at least some of the additives may be present during the polymerization e.g. one or dlscharge rate. so adjusied that the p l of the polymer solution in the reactor was maintalned at 1 more The Chemicals may as 40 litre. The polymerization temperature was about 25 C. such, but IS IS preferred to distribute them in al1qu1d,or Variation in the amounts of the metal organic liquids, that are used as dispersing agents in the ponents gave the results listed in the table polymerization, and/or to disperse them in one or Prior to Curing, 100 g f terpolymer were mixed with several of the liquid or liquified comonomers to be em- 5 g fZ O 1 g Steal-it; acid, 50 g f HAF eathoh black, p y Fiiiers such as Whiting, kaoiih and Carbon l g of Vulkacit Thiuram, 0.5 g of Vulkacit Mercapto black, and so-called extender oils, may also be added; if d 1,5 g f l h F the ll t r l m rs, except so desired, this may be done during the polymerization. the Mooney 39 terpolymert were mixed with 2 5 g f Oil After being cured, the copolym r Whether not (Cirocosol 42 XH). The mixture was cured at 160 C. mixed with other rubbers, such as butyl rubber or SBR, The properties of the products are shown in the table.

TABLE Catalyst composition, mnlole/l.

Ethyl- Polymer composition, percent by weight Properties of the cured rubber Mooney Curing Tensile Elongation Permanent 300% aluminum old, ML l Pro- Etliylidcno Eth- Limo, strength, at rupture, set, modulus, dichloride n.C4H Li V0 C1 g./l. 100 C. pylcne norbornene ylenc niin. kgJcm. percent prrcont kg/rm.

. i t 5 275 680 J 66 1.9 l). 1 0. .2 16 lid 49 .1. O l 18. 96 7- 5 280 640 x 83 15 268 530 (i ll)? I 2. 5 235 HUI) 1;; 3l

lb (I. U it) (18 51 1. ll 11.50 1 7 5 280 050 70 15 .164 570 5 J2 5 .263 Till) h' 53 Ll. 0.1 l) it] All Ill 1. 5h HI. (1.) 1 7. 5 2m G30 7 71 1.) 24!) 500 5 .ll

1 2.1g 751:0 17 it;

lnl U. (r (I 2]. '1 ii!) lb 2.10 51.90 1 7v 5 262 5) n 3x 15 J50 430 ii lTl What is claimed is:

dispersing agent, and an organo-alkali metal com-.

pound, said organo-alkali compound being present in an amount of from about 2 mole percent up to 60 mole percent, based on the amount of aluminum compound.

2. Process according to claim 1, wherein the organic alkali metal compound is an organic lithium compound.

3. Process according to claim 2, wherein the organic lithium compound is normal butyl lithium.

4. Process according to claim 1 wherein the organic I alkali metal compound is present in an amount of -40 mole percent based on the amount of the aluminum compound.

5. A process according to claim 1 wherein the a-alkene is selected from the group consisting of propylene, butene-l, pentene-l, hexene-l, octene-l, 4- methylpentene-l, styrene, a-methyl-styrene, and the polyunsaturated hydrocarbon compound is selected from the group consisting of l-3-butadiene, isoprene, 2,3-dimethyl butadiene, l-3,2-ethyl butadiene-l-3, piperylene, myrcene, allene, l,2-butadiene, 1,4,9- decatrienes, l-4-hexadiene, 1,5-hexadiene, 4-methyl hexadiene-l-4, alkyl norbonadiene, alkylidene norbornenes in which the alkylidene group contains up to 20 carbon atoms, alkenyl norberrenes in which the alkenyl group contains up to 20 carbon atoms, dicyclo (2,2,0)- heptane, dicyclo-(2,2,2)-octane, dicyclo-(3,2,l)-octane, dicyclo-(3,2,2)-nonane, 4,7,8,9-tetrahydroindene, isopropylidene tetrahydroindene, dicyclopentadiene and hexadiene 1-4.

6. The process according to claim 1, wherein said vanadium compound is VOCl or VOCl 7. The process according to claim 1, wherein said organoaluminum dihalide dichloride.

8. The process according to claim 1 wherein the ratio between said aluminum compound and said vanadium compound is between 1:1 and :1.

9. The process according to claim 8 wherein said ratio is between 3:1 and 15:1.

is mono-ethyl-aluminum 

2. Process according to claim 1, wherein the organic alkali metal compound is an organic lithium compound.
 3. Process according to claim 2, wherein the organic lithium compound is normal butyl lithium.
 4. Process according to claim 1 wherein the organic alkali metal compound is present in an amount of 10- 40 mole percent based on the amount of the aluminum compound.
 5. A process according to claim 1 wherein the Alpha -alkene is selected from the group consisting of propylene, butene-1, pentene-1, hexene-1, octene-1, 4-methylpentene-1, styrene, Alpha -methyl-styrene, and the polyunsaturated hydrocarbon compound is selected from the group consisting of 1- 3-butadiene, isoprene, 2,3-dimethyl butadiene, 1-3,2-ethyl butadiene-1-3, piperylene, myrcene, allene, 1,2-butadiene, 1,4,9-decatrienes, 1-4-hexadiene, 1,5-hexadiene, 4-methyl hexadiene-1-4, alkyl norbonadiene, alkylidene norbornenes in which the alkylidene group contains up to 20 carbon atoms, alkenyl norberrenes in which the alkenyl group contains up to 20 carbon atoms, dicyclo (2,2,0)-heptane, dicyclo-(2,2,2)-octane, dicyclo-(3,2,1)-octane, dicyclo-(3,2,2)-nonane, 4,7,8,9-tetrahydroindene, isopropylidene tetrahydroindene, dicyclopentadiene and hexadiene 1-4.
 6. The process according to claim 1, wherein said vanadium compound is VOCl3 or VOCl4.
 7. The process according to claim 1, wherein said organoaluminum dihalide is mono-ethyl-aluminum dichloride.
 8. The process according to claim 1 wherein the ratio between said aluminum compound and said vanadium compound is between 1:1 and 100:1.
 9. The process according to claim 8 wherein said ratio is between 3:1 and 15:1. 